1. Field of the Invention
The present invention relates generally to the field of internal combustion engine injection systems. More particularly, the invention relates to a technique for controlling spray characteristics of a spray assembly by introducing fluid swirl near the exit of an outwardly opening nozzle.
2. Description of the Related Art
In fuel-injected engines, it is generally considered desirable that each injector delivers approximately the same quantity of fuel in approximately the same temporal relationship to the engine for proper operation. It is also well known that the fuel-air mixture affects the combustion process and the formation of pollutants, such as sulfur oxides, nitrogen oxides, hydrocarbons, and particulate matter. Although combustion engines utilize a variety of mixing techniques to improve the fuel-air mixture, many combustion engines rely heavily on spray assemblies to disperse fuel throughout a combustion chamber. These spray assemblies may produce a variety of spray patterns, such as a hollow or solid conical spray pattern, which affect the overall fuel-air mixture in the combustion chamber. It is generally desirable to provide a uniform fuel-air mixture to optimize the combustion process and to eliminate pollutants. However, conventional combustion engines continue to operate inefficiently and produce pollutants due to poor fuel-air mixing in the combustion chamber.
Accordingly, the present technique provides various unique features to overcome the disadvantages of existing spray systems and to improve the fuel-air mixture in combustion engines. In particular, unique features are provided to enhance the fluid flow through an outwardly opening nozzle assembly to provide desired spray characteristics.
The present technique offers a design for internal combustion engines that contemplates such features. The technique is applicable to a variety of fuel injection systems, and is particularly well suited to pressure pulsed designs, in which fuel is pressurized for injection into a combustion chamber by a reciprocating electric motor and pump. However, other injection system types may benefit from the technique described herein, including those in which fuel and air are admitted into a combustion chamber in mixture. Accordingly, the present technique comprises a system and method for controlling fluid flow characteristics in a nozzle assembly. An outwardly opening poppet is movably disposed in an axial conduit to control fluid flow through a forward portion of the axial conduit. A fluid conduit is coupled to the forward portion at an angle configured to provide a desired degree of fluid swirl through the forward portion. The outwardly opening nozzle assembly produces a spray having geometrical characteristics correlated to the desired degree of fluid swirl.
In one aspect, the present technique provides a nozzle comprising an axial conduit, a plurality of fluid conduits, and an outwardly opening poppet disposed in the axial conduit. The axial conduit comprises rear and forward portions. The plurality of fluid conduits are coupled to the forward portion and include lateral portions configured for controlling fluid swirl through the forward portion. The outwardly opening poppet is configured for controlling fluid flow through the forward portion.
In another aspect, the present technique provides a combustion engine comprising a combustion chamber, an ignition assembly and a nozzle assembly coupled to the combustion chamber, and a fuel delivery assembly coupled to the nozzle assembly. The nozzle assembly comprises an outwardly opening flow controller disposed in an axial conduit and a fuel conduit coupled to a forward portion of the axial conduit. The fuel conduit also includes an angular portion configured for controlling fuel swirl through the forward portion.
In another aspect, the present technique provides a method for producing a spray. The method comprises manipulating an outwardly opening nozzle to control flow through a forward portion of an axial passage. The method also comprises feeding fluid angularly to the forward portion to rotate the fluid and control geometrical characteristics of a spray formed at an exit of the forward portion.